Download SERVICE MANUAL - Sharp Pocket Computers

T
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PC-1280
8-8. Precautions
8-9. Display side cabinet and keyboard side cabinet
• All components must be closely attached to the PWB and soldered.
•When the LSI is replaced, use KR19RAM to solder with (see
Service Information PS-009).
• The 0.1 µ.F ceramic capacitor (RC-KZ1054CCZZ) inserted across
the KON pin of GA (pin 26) and the VGG side of the 0.033µ.F
must be handled in the following manner:
The above two cabinets are mated together with the spring pin in
use. To replace one of the cabinets, it is possible to remove the
spring pin by scraping off the cabinet body using such as wire cutter,
but the spring pin once removed may not be used again.
9. Check-Out with the Test Program
A test program is contained in the ROM.
•Check item
(1) RAM card read after
(2) 11-pin connector 1/0
(3) 15-pin connector 1/0
NOTE: The above item
• The capacitor must be inserted to the 11-pin connector in the
following manner:
write test
line tests
line tests
(3) is not used by the PC-1280.
• Tools required
The PC-1360 special tool UKOGC3020CSZZ (price rank: BC) is
used for (2) and (3).
• Description
The RAM contents must be saved on such as tape before conducting
the above test item (1 ), because the program and data are destroyed
during the test.
OFF)
(Power
Turn power on with the following
four keys depressed
at the same time.
···~GIJIE]IQI
PC-1280···
• The resistor (1 OOkll) must be inserted in the following manner:
PC-1475
J···!2J ~
I
(MENU)
I I:RAM
ITl[B]
2:11PIN
3:15PIN
Type [I)
• The diode must be inserted in the following manner:
(I)
RAM test
(2)
11-pin check
Type [2J
Type [ID
(3)
23
POWER switch
~----•(Power
28
__
Tu_be_2_7
.,
NOTE-2:
• See the table below for the size of jumper wire.
Size
140
J2
40
J3
105
• The capacitor (RC-K1E104HCZZ)
in the following manner:
OFF)
•1
NOTE-1:
J1
15-pin check
(Not necessary for the PC-1280)
x 2 pieces must be inserted
-8-
Power can be turned off while the above message is on
display.
If the test program fails to start, check keys first.